Thermal control for electronic devices

ABSTRACT

A method for temperature control. In some embodiments, the method includes sensing a first temperature of an electronic device, determining that the first temperature exceeds a first threshold, and increasing a power supplied to a thermoelectric cooler thermally connected to the electronic device. The increasing of the power may include increasing the power in response to determining that the first temperature exceeds the first threshold.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application claims priority to and the benefit of U.S.Provisional Application No. 62/985,837, filed Mar. 5, 2020, entitled“THERMAL CONTROL DEVICE MANAGEMENT FOR STORAGE DEVICE”, the entirecontent of which is incorporated herein by reference.

FIELD

One or more aspects of embodiments according to the present disclosurerelate to electronic devices, and more particularly to a system andmethod for thermal control of electronic devices.

BACKGROUND

Electronic devices that dissipate heat may be cooled, in operation, toavoid exceeding a maximum-rated operating temperature, and to avoiddamage or unreliable operation that may result from operation at a hightemperature. Some cooling method may use air flow to cool electronicdevices and may need significant volume for ducts or passages carryingcooling air, and for heat exchangers such as finned surfaces, fortransferring heat to the cooling air.

Thus, there is a need for an improved system and method for cooling.

SUMMARY

In some embodiments, a cooling system uses a thermoelectric cooler toextract heat from an electronic device at a greater rate than unassistedconduction of heat would produce. The thermoelectric cooler may conductthe heat to a heat sink (e.g., a finned heat sink cooled by coolingair), which may operate at a higher temperature (because of theheat-pumping operation of the thermoelectric cooler) than the maximumoperating temperature of the electronic device. As a result, thetemperature change of the cooling air may be greater than it would beabsent the thermoelectric cooler, and the cooling air may carry awaymore heat per unit volume of cooling air, than it would absent thethermoelectric cooler. This may make it possible to achieve adequatecooling with a smaller heat sink, and with smaller cooling air passages,than would be possible absent the thermoelectric cooler.

A control system may monitor the temperature at one or more points inthe system and adjust the power supplied to the thermoelectric cooleraccordingly (e.g., increasing the power at relatively high systemtemperatures, and decreasing the power at relatively low systemtemperatures). The control system may also monitor the ambient humidityand avoid increasing the power supplied to the thermoelectric cooler(instead throttling the activity rate of the electronic device) when thetemperature at any point in the system approaches the dew point.

According to an embodiment of the present disclosure, there is provideda method for temperature control, the method including: sensing a firsttemperature of an electronic device; determining that the firsttemperature exceeds a first threshold; and increasing a power suppliedto a thermoelectric cooler thermally connected to the electronic device,wherein the increasing of the power includes increasing the power inresponse to determining that the first temperature exceeds the firstthreshold.

In some embodiments: the power supplied to the thermoelectric cooler isan average power supplied to the thermoelectric cooler; and theincreasing of the power includes modifying a duty cycle of apulse-width-modulated drive current applied to the thermoelectriccooler.

In some embodiments, the method further includes sensing a secondtemperature of the electronic device.

In some embodiments, the method further includes: determining that thesecond temperature is equal to or less than the first threshold;determining that the second temperature is within a tolerancetemperature range; and decreasing the power supplied to thethermoelectric cooler.

In some embodiments, the method further includes: determining that thesecond temperature is equal to or less than the first threshold;determining that the second temperature is outside a tolerancetemperature range; and decreasing the power supplied to thethermoelectric cooler to a power level at most approximately equal to afirst power level.

In some embodiments, the method further includes sensing a thirdtemperature of the electronic device.

In some embodiments, the method further includes: determining that thethird temperature is within the tolerance temperature range; and sensinga fourth temperature of the electronic device.

In some embodiments, the method further includes, determining that thesecond temperature exceeds the first threshold; determining that: thepower supplied to the thermoelectric cooler is at a drive limit, or athird temperature is less than a second threshold; and limiting anactivity rate of the electronic device, wherein the second threshold isbased on a first humidity.

In some embodiments, the method further includes: sensing the firsthumidity; and determining a dew point based on the first humidity,wherein the second threshold is based on the dew point.

In some embodiments, the third temperature is the second temperature.

In some embodiments, the method further includes sensing the thirdtemperature, wherein: the sensing of the second temperature includessensing the second temperature with a first temperature sensor; and thesensing of the third temperature includes sensing the third temperaturewith a second temperature sensor different from the first temperaturesensor.

In some embodiments, the electronic device is a central processing unit.

In some embodiments, the sensing of the first temperature of theelectronic device includes sensing a temperature of a controller of asolid state drive.

In some embodiments, the sensing of the first temperature of theelectronic device includes sensing a temperature of a memory componentof a solid state drive.

According to an embodiment of the present disclosure, there is provideda system, including: a processing circuit; a memory; and a firstthermoelectric cooler, the memory storing instructions that, whenexecuted by the processing circuit, cause the processing circuit to:cause a temperature sensor to sense a first temperature of a first solidstate drive; determine that the first temperature exceeds a firstthreshold; and cause a first drive circuit to increase a power suppliedto the first thermoelectric cooler, the first thermoelectric coolerbeing thermally connected to the first solid state drive.

In some embodiments, the system includes a first rack including: thefirst solid state drive; and a second solid state drive, different fromthe first solid state drive, wherein the instructions further cause theprocessing circuit to cause a second drive circuit to increase a powersupplied to a second thermoelectric cooler thermally connected to thesecond solid state drive.

In some embodiments, the system further includes a second rackincluding: a third solid state drive, wherein the instructions furthercause the processing circuit to cause a third drive circuit to maintaina power supplied to a third thermoelectric cooler thermally connected tothe third solid state drive.

In some embodiments, the instructions further cause the processingcircuit to cause the temperature sensor to sense a second temperature ofthe first solid state drive.

In some embodiments, the instructions further cause the processingcircuit to: determine that the second temperature is equal to or lessthan the first threshold; determine that the second temperature iswithin a tolerance temperature range; and cause the first drive circuitto decrease the power supplied to the first thermoelectric cooler.

According to an embodiment of the present disclosure, there is provideda system, including: means for processing; a memory; and a firstthermoelectric cooler, the memory storing instructions that, whenexecuted by the means for processing, cause the means for processing to:sense a first temperature of a first solid state drive; determine thatthe first temperature exceeds a first threshold; and increase a powersupplied to the first thermoelectric cooler, the first thermoelectriccooler being thermally connected to the first solid state drive.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present disclosure willbe appreciated and understood with reference to the specification,claims, and appended drawings wherein:

FIG. 1A is a schematic perspective drawing of an electronic device and athermoelectric cooler, according to an embodiment of the presentdisclosure;

FIG. 1B is a schematic perspective drawing of solid state drive and athermoelectric cooler, according to an embodiment of the presentdisclosure;

FIG. 2A is a temperature range decision diagram, according to anembodiment of the present disclosure; and

FIG. 2B is a flow chart of a method for cooling an electronic device,according to an embodiment of the present disclosure; and

FIG. 3 is a block diagram of racks containing solid state drives,according to an embodiment of the present disclosure; and

FIG. 4 is a flow chart of a method for cooling a plurality of solidstate drives, according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of exemplary embodiments of asystem and method for thermal control for electronic devices provided inaccordance with the present disclosure and is not intended to representthe only forms in which the present disclosure may be constructed orutilized. The description sets forth the features of the presentdisclosure in connection with the illustrated embodiments. It is to beunderstood, however, that the same or equivalent functions andstructures may be accomplished by different embodiments that are alsointended to be encompassed within the scope of the disclosure. Asdenoted elsewhere herein, like element numbers are intended to indicatelike elements or features.

In some embodiments, a cooling system uses a thermoelectric cooler toextract heat from an electronic device at a greater rate than unassistedconduction of heat would produce. The thermoelectric cooler may conductthe heat to a heat sink (e.g., a finned heat sink cooled by coolingair), which may operate at a higher temperature (because of theheat-pumping operation of the thermoelectric cooler) than the maximumoperating temperature of the electronic device. This may make itpossible to achieve adequate cooling with a smaller heat sink, and withsmaller cooling air passages, than would be possible absent thethermoelectric cooler.

A control system may monitor the temperature at one or more points inthe system and adjust the power supplied to the thermoelectric cooleraccordingly (e.g., increasing the power at relatively high systemtemperatures, and decreasing the power at relatively low systemtemperatures). The control system may also monitor the ambient humidityand avoid increasing the power supplied to the thermoelectric cooler(instead throttling the activity rate of the electronic device) when thetemperature at any point in the system approaches the dew point. Forexample, if the measured temperature exceeds a first threshold, thecontrol system may (i) if the temperature everywhere in the system iswell above the dew point, and if the driver for driving thethermoelectric cooler has sufficient reserve drive capacity, increasethe power supplied to the thermoelectric cooler, or (ii) if thetemperature is too close to the dew point, or the driver for driving thethermoelectric cooler lacks sufficient reserve drive capacity, throttlethe electronic device to reduce the rate at which it generates heat.

Some embodiments have various advantageous characteristics, includingimproved processing power or storage capacity within a fixed volume,improved heat dissipation, improved network efficiency, and energyreduction.

Referring to FIG. 1A, in some embodiments, an electronic device 105 maybe thermally connected to a thermoelectric cooler 110. As used herein,two elements being “thermally connected” means that heat may readilyflow from one to the other (e.g., as a result of the two elements beingin contact, or secured together at mating surfaces, e.g., with a layerof thermal interface material between them to compensate for anyimperfect flatness of the mating surfaces). The thermoelectric coolercan be implemented in a device that utilizes Peltier effect, forexample. In this case, the device brings heat from one side to the otherside when DC electric current flows through it. This operation can beused in some embodiments to pump heat out of the electronic device 105.The temperature of the electronic device 105 may be sensed with a firsttemperature sensor 115, and a suitable control signal may be calculatedfrom the sensed temperature, by a processing circuit (discussed infurther detail below) connected to the first temperature sensor 115 andconfigured to read the first temperature sensor 115 (e.g., through ananalog to digital converter). In some embodiments, the first temperaturesensor 115 is “on chip”, i.e., on the same chip as the processingcircuit. For simplicity, only two temperature sensors are shown in FIG.1A. In some embodiments, there may be many more temperature sensorsdistributed in any type of configuration (and the temperature sensorsmay be grouped into first and second groups, etc.). Similarly, there maybe many more humidity sensors than the one shown, distributed in anytype of configuration (and the humidity sensors may be grouped intofirst and second groups, etc.).

The control signal may be fed to a thermoelectric cooler drive circuit120; the thermoelectric cooler drive circuit 120 may then apply a drivecurrent (e.g., a drive current proportional to the control signal) tothe thermoelectric cooler 110. The processing circuit may be, or may bepart of, the electronic device 105, as shown in FIG. 1A. As mentionedbelow, the processing circuit may include, but not be limited to, anFPGA, an ASIC, a dedicated processor, or the like. The processingcircuit may further be connected to a water vapor pressure sensor, whichmay also be referred to as a humidity sensor 125 herein. The humiditysensor 125 may be used to calculate the dew point, and the processingcircuit may, in generating the control signal, ensure that furthercooling is not performed when any sensed temperature in the systemapproaches (e.g., is within a margin (which may be referred to as the“dew point margin”) of, e.g., within 3 degrees Celsius of) the dewpoint. The system may include a second temperature sensor 130, which maybe at a point in the system (e.g., directly on the cold side of thethermoelectric cooler 110) which in operation is likely to be thecoldest point in the system, and which, in operation, may be at a lowertemperature than the first temperature sensor 115.

The electronic device 105 may be any electronic device that dissipatesheat and that is capable of being throttled (as discussed in furtherdetail below). The electronic device 105 may be, for example, a centralprocessing unit of a computer (e.g., of a server), or a solid statedrive, or a controller of a solid state drive. In the embodimentillustrated in FIG. 1B, the electronic device 105 is a solid statedrive, which includes a solid state drive controller 135 and memory(e.g., a flash memory) 140. In such an embodiment, it may be that thetemperature of the memory 140 differs, in operation, from thetemperature of the solid state drive controller 135. It may also be thatthe maximum operating temperature of the memory 140 differs the maximumoperating temperature of the solid state drive controller 135. As such,in some embodiments the processing circuit may make cooling decisions(as discussed in further detail below, in the context of FIG. 2) basedon the temperature sensed by the first temperature sensor 115 and insome embodiments the processing circuit may make cooling decisions basedon the temperature sensed by the second temperature sensor 130.

FIG. 2A shows a graph of temperature, with high temperature at the topand low temperature at the bottom. Also shown on the graph are (i) afirst threshold 205, and a range of temperatures, referred to as a“tolerance temperature range” 210, which may be a range of acceptableoperating temperatures. As shown on FIG. 2A, and discussed in furtherdetail below, when the sensed temperature is higher than the tolerancetemperature range 210 and exceeds the first threshold 205, the systemmay increase the power supplied to the thermoelectric cooler 110 or (ifthe thermoelectric cooler drive circuit 120 is not capable of deliveringmore power to the thermoelectric cooler 110, or if a temperature in thesystem is approaching the dew point) limit an activity rate of theelectronic device (i.e., “throttle” the electronic device). Limiting theactivity rate of the electronic device may entail, if the electronicdevice is a solid state drive, limiting the rate at which the solidstate drive performs operations including, but not limited to, read,write, erase, and garbage collection operations. Limiting the activityrate of the electronic device may entail, if the electronic device is acentral processing unit, transitioning the central processing unit to alow power consumption state, in which the central processing unit may,for example, shut down one or more cores (if the central processing unitincludes a plurality of cores), or in which the central processing unitperforms operations at a reduced rate to reduce power consumption.

If the temperature is less than the first threshold 205 and within thetolerance temperature range 210, the system may decrease the powersupplied to the thermoelectric cooler 110. If the temperature is belowthe lower end of the tolerance temperature range 210, the system maydecrease the power to be equal to or less than a first power level(e.g., it may shut off the power supplied to the thermoelectric cooler110 entirely). The first power level may be a power level that issufficiently small to result in an acceptably small risk of any part ofthe system reaching the dew point, or it may be zero.

FIG. 2B shows a flow chart of a method for cooling a solid state drive,in some embodiments. At 215, the solid state drive controller 135 causesa temperature sensor to sense the temperature of the controller chip orof the entire solid state drive. At 220, the solid state drivecontroller 135 tests whether the sensed temperature is within thetolerance temperature range 210. If it is, no change is made to thepower supplied to the thermoelectric cooler 110, and the system returnsto sensing the temperature, at 215. While FIG. 2B is explained here inthe context of an embodiment in which the method is performed by a solidstate drive controller 135, in some embodiments the method could equallybe performed by any suitable processor (FGPA, ASIC, etc.).

If the sensed temperature is not within the tolerance temperature range210, the solid state drive controller 135 tests, at 225, whether thetemperature exceeds the first threshold 205. If the temperature exceedsthe first threshold 205, the solid state drive controller 135 tests, at230 whether a limit on the power supplied to the thermoelectric cooler110 has been reached (as discussed in further detail below), and, ifnot, it allows, at 235, the solid state drive to operate without a limiton an activity rate of the solid state drive, and causes thethermoelectric cooler drive circuit 120 to increase, at 240, the power(e.g., the average power) supplied to the thermoelectric cooler 110,e.g., by (i) increasing the drive current applied to the thermoelectriccooler 110, or (ii) increasing the drive voltage applied to thethermoelectric cooler 110, or (iii) increasing the duty cycle of apulse-width-modulated drive current or voltage applied to thethermoelectric cooler 110, or (iv) modifying any waveform of the drivecurrent or voltage.

The limit on the power supplied to the thermoelectric cooler 110 may bereached, for example, (i) as a result of the thermoelectric cooler drivecircuit 120 already applying the maximum power it is capable ofproviding to the thermoelectric cooler 110, or (ii) as a result of atemperature in the system being less than the dew point plus the dewpoint margin. The dew point may be calculated by the solid state drivecontroller 135 or equivalent processing circuit from the sensed humidityusing a function (e.g., a polynomial or a cubic spline) thatapproximates the functional form of the dew point as a function of thesensed humidity, or it may be obtained from a lookup table listing thedew point as a function of sensed humidity. The temperature that iscompared to the dew point may be the same temperature (sensed by thefirst temperature sensor 115) that is compared to the first threshold205 and to the tolerance temperature range 210, or it may be atemperature (e.g., a lower temperature) sensed by the second temperaturesensor 130 (as discussed, and for the reasons discussed, above).

If the solid state drive controller 135 determines, at 230, that a limiton the power supplied to the thermoelectric cooler 110 has been reached,then instead of further increasing the power supplied to thethermoelectric cooler 110 it may start, at 245, throttling the solidstate drive, i.e., it may limit the activity rate of the solid statedrive as discussed above.

If, at 225, the solid state drive controller 135 determines that thesensed temperature does not exceed the first threshold 205, it tests, at250, whether the sensed temperature is within the tolerance temperaturerange 210. If it is, it causes the thermoelectric cooler drive circuit120 to decrease, at 255, the power supplied to the thermoelectric cooler110. If the sensed temperature is not within the tolerance temperaturerange 210 (e.g., if it is below the lower end of the tolerancetemperature range 210), the solid state drive controller 135 maydecrease, at 260, the power to be equal to or less than a first powerlevel (e.g., it may cause the thermoelectric cooler drive circuit 120 toshut off the power supplied to the thermoelectric cooler 110 entirely).

After having made any adjustments to the power supplied to thethermoelectric cooler 110 or to the activity rate of the solid statedrive, the system waits, at 265 or at 270, during an interval of timeselected to be approximately equal to the thermal reaction time of thesystem (e.g., to the delay between when a change is made in the powersupplied to the thermoelectric cooler 110 and when most (e.g., 65%) ofthe resulting temperature change is present at the first temperaturesensor 115). The system then senses the temperature again, at 275 or at215, and the process repeats.

The method illustrated in FIGS. 2A and 2B may be performed in ananalogous manner if the electronic device is another kind of electronicdevice that dissipates heat and that is capable of being throttled,i.e., of operating at a reduced activity rate, and dissipating, whenoperating at the reduced activity rate, a reduced amount of power. Inembodiments in which separate temperature control requirements apply todifferent components of a system (e.g., in a solid state drive having afirst set of requirements for the solid state drive controller 135 and asecond set of requirements for the memory (e.g., the flash memory) 140),a respective first threshold 205 and tolerance temperature range 210 maybe defined for each of the components. The result of the test at 220 maythen be considered to be the logical AND of the result of each of thetwo sensed temperatures (e.g., the result may be yes, or “Y” if it isyes when evaluated for each of the two components), and the result ofthe test at 225 may be considered to be the logical OR of the result foreach of the two sensed temperatures. In some embodiments, the aboveprocess can be performed using a machine learning module (host side,device side, etc.) that can monitor data representing the historicalperformance of the device and throttle accordingly. Such a machinelearning module may be based on any suitable machine learning model, ormodels, including without limitation artificial neural networks,decision trees, support vector machines, regression analysis, Bayesiannetworks, and genetic algorithms.

Referring to FIG. 3, in some embodiments a plurality of racks 301, 302(of which two are shown) may be in place at a facility (e.g., at aserver farm); each rack 301, 302 may house a plurality of solid statedrives 311, 312, 313, 314. Each of the solid state drives may implementtemperature control as described above, or, in some embodiments, ashared controller 320 may manage, e.g., all or a group of the solidstate drives, or all or a group of the solid state drives in one of theracks 301, 302. In some embodiments, the shared controller 320 can bepart of one device, a standalone controller, host-side, etc., and it caninclude any suitable circuity (e.g., processor, FGPA, ASIC, etc.).Further, the shared controller may communicate with electronic devicesover a protocol such as Ethernet or any other suitable protocol withwhich the electronic devices are compatible. For example, the electronicdevices may include Ethernet-enabled SSDs that can receive commands fromthe controller to send or receive temperature or humidity data and powerthrottling commands. The shared controller 320 may collect sensedtemperatures from all of the solid state drives that it manages, andsend commands to each of these solid state drives, instructing eachdrive regarding the power to be supplied to the thermoelectric cooler110 and regarding whether to limit the activity rate of the solid statedrive. In some embodiments the shared controller 320 can have a generalview of the system as a whole and throttle power at the device level,server level, rack level, or cluster level in a data center having theseSSD devices. Further, a machine learning module may be constantlymonitoring and improving the power routing based on historicalperformance to achieve optimal power efficiency and minimizing heatlosses. Such a machine learning module may be based on any suitablemachine learning model, or models, including without limitationartificial neural networks, decision trees, support vector machines,regression analysis, Bayesian networks, and genetic algorithms.

In an embodiment including a plurality of racks 301, 302 each of whichmay house a plurality of solid state drives, it may be the case thatheat is to some extent transferred between the solid state drives in arack (but not between solid state drives in different racks), and, asillustrated in FIG. 4, the shared controller 320 may, for example, inresponse to sensing, at 405, a temperature of a first solid state drive311, and determining, at 410, that the temperature exceeds the firstthreshold 205, cause thermoelectric cooler drive circuits 120 toincrease the power supplied to the thermoelectric cooler 110 in both thefirst solid state drive 311, at 415, and, at 420, in a second solidstate drive 312 that is in the same rack 301, but not to change, i.e.,to maintain, at 425, the power supplied to the thermoelectric cooler 110in a third solid state drive 313 that is in another rack 302. Moreover,in some embodiments the shared controller 320 may command thatthrottling occur in a plurality of drives that are near each other(e.g., in the same rack, or in the top half or bottom half of one rack)when any, or a few, of the thermoelectric cooler drive circuits 120 inthe plurality of drives has run out of reserve drive capacity. Such anapproach may be advantageous when significant heat sharing is occurringbetween the drives, in which case throttling a single drive may have asmaller effect on its temperature than if it were a standalone drive,isolated from other source of heat.

Any of the components or any combination of the components described(e.g., in any system diagrams included herein) may be used to performone or more of the operations of any flow chart included herein.Further, (i) the operations are example operations, and may involvevarious additional steps not explicitly covered, and (ii) the temporalorder of the operations may be varied.

In some embodiments, the methods described herein are performed by aprocessing circuit, which may (e.g., through one or more analog todigital converters connected to the processing circuit) read sensors andwhich may (e.g., through one or more digital to analog convertersconnected to the processing circuit) send control signals (e.g., to thethermoelectric cooler drive circuit 120). The solid state drivecontroller 135 may be a processing circuit, for example. The term“processing circuit” is used herein to mean any combination of hardware,firmware, and software, employed to process data or digital signals.Processing circuit hardware may include, for example, applicationspecific integrated circuits (ASICs), general purpose or special purposecentral processing units (CPUs), digital signal processors (DSPs),graphics processing units (GPUs), and programmable logic devices such asfield programmable gate arrays (FPGAs). In a processing circuit, as usedherein, each function is performed either by hardware configured, i.e.,hard-wired, to perform that function, or by more general-purposehardware, such as a CPU, configured to execute instructions stored in anon-transitory storage medium. A processing circuit may be fabricated ona single printed circuit board (PCB) or distributed over severalinterconnected PCBs. A processing circuit may contain other processingcircuits; for example, a processing circuit may include two processingcircuits, an FPGA and a CPU, interconnected on a PCB.

As used herein, when a first quantity (e.g., a first variable) isreferred to as being “based on” a second quantity (e.g., a secondvariable) it means that the second quantity influences the firstquantity, e.g., the second quantity may be an input (e.g., the onlyinput, or one of several inputs) to a function that calculates the firstquantity, or the first quantity may be equal to the second quantity, orthe first quantity may be the same as (e.g., stored at the same locationor locations in memory) as the second quantity.

As used herein, the term “or” should be interpreted as “and/or”, suchthat, for example, “A or B” means any one of “A” or “B” or “A and B”. Itwill be understood that, although the terms “first”, “second”, “third”,etc., may be used herein to describe various elements, components,regions, layers and/or sections, these elements, components, regions,layers and/or sections should not be limited by these terms. These termsare only used to distinguish one element, component, region, layer orsection from another element, component, region, layer or section. Thus,a first element, component, region, layer or section discussed hereincould be termed a second element, component, region, layer or section,without departing from the spirit and scope of the inventive concept.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the inventiveconcept. As used herein, the terms “substantially,” “about,” and similarterms are used as terms of approximation and not as terms of degree, andare intended to account for the inherent deviations in measured orcalculated values that would be recognized by those of ordinary skill inthe art. As used herein, the singular forms “a” and “an” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising”, when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof. As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items. Expressions such as “at least one of,” when preceding alist of elements, modify the entire list of elements and do not modifythe individual elements of the list. Further, the use of “may” whendescribing embodiments of the inventive concept refers to “one or moreembodiments of the present disclosure”. Also, the term “exemplary” isintended to refer to an example or illustration. As used herein, theterms “use,” “using,” and “used” may be considered synonymous with theterms “utilize,” “utilizing,” and “utilized,” respectively.

It will be understood that when an element or layer is referred to asbeing “on”, “connected to”, “coupled to”, or “adjacent to” anotherelement or layer, it may be directly on, connected to, coupled to, oradjacent to the other element or layer, or one or more interveningelements or layers may be present. In contrast, when an element or layeris referred to as being “directly on”, “directly connected to”,“directly coupled to”, or “immediately adjacent to” another element orlayer, there are no intervening elements or layers present.

Any numerical range recited herein is intended to include all sub-rangesof the same numerical precision subsumed within the recited range. Forexample, a range of “1.0 to 10.0” or “between 1.0 and 10.0” is intendedto include all subranges between (and including) the recited minimumvalue of 1.0 and the recited maximum value of 10.0, that is, having aminimum value equal to or greater than 1.0 and a maximum value equal toor less than 10.0, such as, for example, 2.4 to 7.6. Any maximumnumerical limitation recited herein is intended to include all lowernumerical limitations subsumed therein and any minimum numericallimitation recited in this specification is intended to include allhigher numerical limitations subsumed therein.

Although exemplary embodiments of a system and method for thermalcontrol for electronic devices have been specifically described andillustrated herein, many modifications and variations will be apparentto those skilled in the art. Accordingly, it is to be understood that asystem and method for thermal control for electronic devices constructedaccording to principles of this disclosure may be embodied other than asspecifically described herein. The invention is also defined in thefollowing claims, and equivalents thereof.

what is claimed is:
 1. A method for temperature control, the methodcomprising: sensing a first temperature of an electronic device;determining that the first temperature exceeds a first threshold; andincreasing a power supplied to a thermoelectric cooler thermallyconnected to the electronic device, wherein the increasing of the powercomprises increasing the power in response to determining that the firsttemperature exceeds the first threshold.
 2. The method of claim 1,wherein: the power supplied to the thermoelectric cooler is an averagepower supplied to the thermoelectric cooler; and the increasing of thepower comprises modifying a duty cycle of a pulse-width-modulated drivecurrent applied to the thermoelectric cooler.
 3. The method of claim 1,further comprising sensing a second temperature of the electronicdevice.
 4. The method of claim 3, further comprising: determining thatthe second temperature is equal to or less than the first threshold;determining that the second temperature is within a tolerancetemperature range; and decreasing the power supplied to thethermoelectric cooler.
 5. The method of claim 3, further comprising:determining that the second temperature is equal to or less than thefirst threshold; determining that the second temperature is outside atolerance temperature range; and decreasing the power supplied to thethermoelectric cooler to a power level at most approximately equal to afirst power level.
 6. The method of claim 5, further comprising sensinga third temperature of the electronic device.
 7. The method of claim 6,further comprising: determining that the third temperature is within thetolerance temperature range; and sensing a fourth temperature of theelectronic device.
 8. The method of claim 3, further comprising:determining that the second temperature exceeds the first threshold;determining that: the power supplied to the thermoelectric cooler is ata drive limit, or a third temperature is less than a second threshold;and limiting an activity rate of the electronic device, wherein thesecond threshold is based on a first humidity.
 9. The method of claim 8,further comprising: sensing the first humidity; and determining a dewpoint based on the first humidity, wherein the second threshold is basedon the dew point.
 10. The method of claim 8, wherein the thirdtemperature is the second temperature.
 11. The method of claim 8,further comprising sensing the third temperature, wherein: the sensingof the second temperature comprises sensing the second temperature witha first temperature sensor; and the sensing of the third temperaturecomprises sensing the third temperature with a second temperature sensordifferent from the first temperature sensor.
 12. The method of claim 1,wherein the electronic device is a central processing unit.
 13. Themethod of claim 1, wherein the sensing of the first temperature of theelectronic device comprises sensing a temperature of a controller of asolid state drive.
 14. The method of claim 1, wherein the sensing of thefirst temperature of the electronic device comprises sensing atemperature of a memory component of a solid state drive.
 15. A system,comprising: a processing circuit; a memory; and a first thermoelectriccooler, the memory storing instructions that, when executed by theprocessing circuit, cause the processing circuit to: cause a temperaturesensor to sense a first temperature of a first solid state drive;determine that the first temperature exceeds a first threshold; andcause a first drive circuit to increase a power supplied to the firstthermoelectric cooler, the first thermoelectric cooler being thermallyconnected to the first solid state drive.
 16. The system of claim 15,wherein the system comprises a first rack comprising: the first solidstate drive; and a second solid state drive, different from the firstsolid state drive, wherein the instructions further cause the processingcircuit to cause a second drive circuit to increase a power supplied toa second thermoelectric cooler thermally connected to the second solidstate drive.
 17. The system of claim 16, wherein the system furthercomprises a second rack comprising: a third solid state drive, whereinthe instructions further cause the processing circuit to cause a thirddrive circuit to maintain a power supplied to a third thermoelectriccooler thermally connected to the third solid state drive.
 18. Thesystem of claim 15, wherein the instructions further cause theprocessing circuit to cause the temperature sensor to sense a secondtemperature of the first solid state drive.
 19. The system of claim 18,wherein the instructions further cause the processing circuit to:determine that the second temperature is equal to or less than the firstthreshold; determine that the second temperature is within a tolerancetemperature range; and the first drive circuit to decrease the powersupplied to the first thermoelectric cooler.
 20. A system, comprising:means for processing; a memory; and a first thermoelectric cooler,memory storing instructions that, when executed by the means forprocessing, cause the means for processing to: sense a first temperatureof a first solid state drive; determine that the first temperatureexceeds a first threshold; and increase a power supplied to the firstthermoelectric cooler, the first thermoelectric cooler being thermallyconnected to the first solid state drive.